Cron

# +--------- Minute (0-59)                    | Output Dumper: >/dev/null 2>&1 
# | +------- Hour (0-23)                      | Multiple Values Use Commas: 3,12,47 
# | | +----- Day Of Month (1-31)              | Do every X intervals: */X  -> 
# | | |                                       | Example: */15 * * * *  Is every 15 minutes 
# | | | +--- Month (1 -12)                    | Aliases: @reboot -> Run once at startup; 
# | | | |                                     | @hourly -> 0 * * * *; 
# | | | | +- Day Of Week (0-6) (Sunday = 0)   | @daily -> 0 0 * * *; @weekly -> 0 0 * * 0; 
# | | | | |                                   | @monthly ->0 0 1 * *; 
# | | | | |                                   | @yearly -> 0 0 1 1 *; 
  * * * * * COMMAND